/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile.visitor;

import proguard.classfile.*;
import proguard.classfile.util.SimplifiedVisitor;

/**
 * This <code>MemberVisitor</code> lets a given <code>MemberVisitor</code> travel to all concrete and abstract
 * implementations of the visited methods in their class hierarchies.
 *
 * @author Eric Lafortune
 */
public class MethodImplementationTraveler extends SimplifiedVisitor implements MemberVisitor {
    private final boolean visitThisMethod;
    private final boolean visitSuperMethods;
    private final boolean visitInterfaceMethods;
    private final boolean visitOverridingMethods;
    private final MemberVisitor memberVisitor;

    /**
     * Creates a new MethodImplementationTraveler.
     * 
     * @param visitThisMethod specifies whether to visit the originally visited methods.
     * @param visitSuperMethods specifies whether to visit the method in the super classes.
     * @param visitInterfaceMethods specifies whether to visit the method in the interface classes.
     * @param visitOverridingMethods specifies whether to visit the method in the subclasses.
     * @param memberVisitor the <code>MemberVisitor</code> to which visits will be delegated.
     */
    public MethodImplementationTraveler(boolean visitThisMethod, boolean visitSuperMethods,
        boolean visitInterfaceMethods, boolean visitOverridingMethods, MemberVisitor memberVisitor) {
        this.visitThisMethod = visitThisMethod;
        this.visitSuperMethods = visitSuperMethods;
        this.visitInterfaceMethods = visitInterfaceMethods;
        this.visitOverridingMethods = visitOverridingMethods;
        this.memberVisitor = memberVisitor;
    }

    // Implementations for MemberVisitor.

    public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod) {
        if (visitThisMethod) {
            programMethod.accept(programClass, memberVisitor);
        }

        if (!isSpecial(programClass, programMethod)) {
            programClass.hierarchyAccept(false, visitSuperMethods, visitInterfaceMethods, visitOverridingMethods,
                new NamedMethodVisitor(programMethod.getName(programClass), programMethod.getDescriptor(programClass),
                    new MemberAccessFilter(0, ClassConstants.ACC_PRIVATE | ClassConstants.ACC_STATIC, memberVisitor)));
        }
    }

    public void visitLibraryMethod(LibraryClass libraryClass, LibraryMethod libraryMethod) {
        if (visitThisMethod) {
            libraryMethod.accept(libraryClass, memberVisitor);
        }

        if (!isSpecial(libraryClass, libraryMethod)) {
            libraryClass.hierarchyAccept(false, visitSuperMethods, visitInterfaceMethods, visitOverridingMethods,
                new NamedMethodVisitor(libraryMethod.getName(libraryClass), libraryMethod.getDescriptor(libraryClass),
                    new MemberAccessFilter(0, ClassConstants.ACC_PRIVATE | ClassConstants.ACC_STATIC, memberVisitor)));
        }
    }

    // Small utility methods.

    private boolean isSpecial(Clazz clazz, Method method) {
        return (method.getAccessFlags() & (ClassConstants.ACC_PRIVATE | ClassConstants.ACC_STATIC)) != 0
            || method.getName(clazz).equals(ClassConstants.METHOD_NAME_INIT);
    }
}
